In the merchandising of products and in the provision of conversation pieces for homes and offices, it is desirable to provide motive power for the merchandising or conversation piece devices by parasiting light from pre-existing light bulbs. Utilizing apparatus such as illustrated and described in copending application Ser. No. 142,995 filed Apr. 23, 1980, it is possible to successfully employ such a parasiting principle even for conventional fluorescent light bulbs. In view of the expensiveness of solar cells, however, it is desirable to maximize the efficiency of such units. When this done, a wider variety of point-of-purchase or other attention-capturing devices may be effectively powered from conventional fluorescent bulbs, and/or existing devices can be powered less expensively.
According to the present invention an energy converting assembly for attachment to an elongated light source, such as a conventional fluorescent tube, is provided that effects up to a 50% power output improvement in current, and up to 25% improvement in voltage, over corresponding devices such as illustrated in copending application Ser. No. 142,995. This unexpectedly significant improvement in power output is generally accomplished by a number of structures and techniques: the solar cell (or cells) is elongated in the dimension of elongation of the fluorescent tube and is held tightly against the bottom surface of the fluorescent tube; the cell and tube are wrapped with a reflector which is capable of reflecting substantially all the light impacting it upon back toward the tube and the solar cell; the reflector extends beyond the solar cell at either end thereof; and the cell surface is cleaned and coated with a temperature-resistant light-reflection minimizing spray.
According to the present invention an assembly is provided for attachment to an elongated light source--such as a conventional fluorescent light bulb--for converting light energy from the bulb into electrical energy, and subsequently for powering a d.c. motor or the like. The assembly includes a solar cell, and an elongated base member to which the solar cell is mounted. The base member may be of a thin relatively rigid material, such as stiff cardboard or plastic, and the solar cell may be mounted thereto by double-faced tape or the like. Electrical interconnections are operatively attached to the solar cell for carrying away electrical energy produced by the cell to a remote location (such as a d.c. motor). Reflective means are provided substantially surrounding the fluorescent tube along the length of the base member for reflecting substantially all the light impinging thereon back toward the light source and the solar cell.
The light reflective means preferably comprises one or more sheets of flexible opaque material having an inner surface thereof of reflective color, preferably flat white. For instance, the opaque flexible material may be cardboard, or paper mounted on cardboard, or paper with Mylar foil on its exterior surface. Alternatively, the opaque flexible material may comprise plastic formed as spring clips form receiving the fluorescent tube therebetween. Holding means are provided for mounting the reflective means around the fluorescent tube, and for holding the solar cell tightly against the bottom surface of the fluorescent tube. Such holding means may be the inherent spring qualities of the flexible material (when plastic), adhesive associated with the reflective sheet (as when cardboard), or an exterior spring clip.
A d.c. motor may conveniently be mounted in association with the energy converting assembly by hanging it from a spring clip which holds the reflective means and solar cell in place. Hanging downwardly from the d.c. motor may be a sign having indicia thereon, and any of the interconnections between motor and sign illustrated in copending application Ser. No. 142,995 filed Apr. 23, 1980 (the disclosure of which is hereby incorporated by reference herein) may be provided. The assembly may readily be utilized as a point-of-purchase device, or may be utilized to effect air movement from the volume surrounding the fluorescent tube, or may power a wide variety of other devices for ornamental, conversational, or functional reasons.
It is the primary object of the present invention to provide an efficient energy converting assembly for utilization with an elongated light source like a fluorescent light bult. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.